Zinc sulphide as a ceramic opacifier



Patented June 20, 1 939 UNITED ,STATES PATENT OFFICE Application July22, 1937, Serial No. 155,103

In Germany July 23, 1936 16 Claims.

A writing instrument having interchangeable leads or the like is alreadyknown which has'two casings movable inside of each other, one of whichhereinafter designated as a feed casing carries the feed actioninstrumentalities, while the other isknown as the guide casing andcontains the leads and their carriers. In the known arrangements, inorder to select the desired lead carrier, the feed casing is rotated.Furthermore, the lead carrier when pushed out is held in place by thefeed casing which is also pushed out and held in that position. In orderto change the lead carrier, the feed casing must be pushed back, rotatedin the guide casing, must engage the other lead carrier and then beagain pushed forward. The withdrawn lead carrier is released from thefeeding case or pushed back by springs during this process.

This manipulation is comparatively bothersome and has led 'to apreference for a device in which the lead carrier is provided with anindividual guide button by which it can be easily brought to anoperative position, and by which it can be withdrawn by the unhooking ofa catch and by being pushed back manually, or by the action of a springwhich throws it back. Such a device has the disadvantage that itssurface is not smooth, since it has the aforementioned buttons. Inaddition, the catch of the lead carrier when brought inposition for useis likely to be loose unintentionally and the lead carrier withdrawnprematurely.

All of these disadvantages have been eliminated by the device of thisapplication which provides a smooth surface on the device and so enablesthe manipulation of the lead carrier from an operative to an inoperativeposition, or vice versa, to be accomplished by a single manipulation.The invention comprises a device having. two casings .which are movableinside of each other and in which the one (the feed casing) carries thefeed action arrangement, while the other (the guide casing) contains thelead carrier. The device is made in such a manner that on the front endof the feed casing, which cannot be turned, a feed bar is attached byits rear end in such a manner that the front end thereof is freelymovable. Thus, when the lead pencil is not vertical, gravitation forcesthe feed'bar and -:'adjusts it.

Through this arrangement, any special adjustment of the lead carrierwhen being pushed out is eliminated. The only manipulation which isnecessary, therefore, is the simple act of turning the device so that a.mark indicating the desired lead carrier lies uppermost where it isvisible to the eye of the user. In this position, the feed barautomatically engages the desired lead carrier, so that the onlymanipulation required is the pressing of the feed casing to bring thelead carrier into position. i

The feed bar can be supported in such a manner that it swings freely ona cylinder jacket or is freely swingable from its rear end in all directions. In the first instance, the feed bar rests :on a rotating crankattached to the feed casing, or it can be set in a ring-like groove inthe bottom ofthe feed casing so that its rear end is freely swingable.The feed casing is subject to action by a recoil spring which pushes itback to its innermost position. In this manner, the feed casing isalways in position for use and does not. have to be pushed back toengage a lead carrier but. need only. be pushed forward. The leadcarriers, which are urged to non-use position by recoil springs, canhave a spring catch which, when in action, snaps into a stay on theouter casing which can be released from the outside. Next, in switchingthe lead carrier, the one in use must be released before the other onecan be pushed up.' It isalso possible and desirable u that each leadcarrier be provided with a guide pin moving in a long slot of the leadcarrier casing and also slidable through a slot of a casing which isattached to the guide casing and which is turnable with the help of theguide pin acting through the slot and which also serves to lock andunlock the lead carriers when in use. This will eliminate a specialmovement for the uncoupling of the lead carrier. All that is requiredfor operation of the device is topress on the feed casing which releasesthe lead carrier which is in the forward position in the device andpositions the next carrier for use.

With the foregoing and other objects in view, the invention consists inthe details of construction, and in the arrangement and combination ofparts to be hereinafter more fully set forth and claimed.

In describing the invention in detail, reference will be had to theaccompanying drawing forming partof this application, wherein likecharacters denote corresponding parts in the several views, and inwhich- Figure 1 illustrates a longitudinal section through a pencilembodying my invention;

Figure 2 illustrates a fragmentary elevation of a portion of the devicewith the casing shown in longitudinal section;

Figure 3 illustrates a slightly enlarged'transverse section on line 3-3of Fig. 1;

tion of rest, to which also returns the lead car-' rier which it hadmoved.

The movements necessary to select a certain lead carrier consist only inthe natural and simple turning of the entire interchangeable device tosuch position as causes the color mark 39 of the desired lead carrier tolie uppermost and visible to the user. The modus operandi can bedescribed concisely as follows:

Look at the desired color mark and press on the feed casing Hi. If byreason of the fact that the device is held on a slant, the color mark isnot exactly at the top, this does not interfere with perfect operation.Because the,

upper reinforced edges 9 of the cross-shaped insertions 3 are sharpenedat the ends, the forepart of the feed bar 26 is enabled to glide easilyinto the desired section of the guide casing I even when slightlyslanting and pushes the de sired lead carrier forward.

.In Figs. 8, 9 and 10, 1 two modified arrangements of the forwardfeeding means are pictured. In both, the feed bar 26, 26 is crankshapedand situated at the front of the feed casing H3 to which it is pivotallyattached. Ac-

cording to the method in Figs. 8, 9, the feed bar 26 is crank-shaped andcarries at its upper end a ball-shaped head 40 which is freely movablein a shoulder piece 4| of the feed casing l8.

In the arrangement of Figs. 10, 11, thefeedbar 26 has a crank 42soldered to it which turns on a pin 43 which is soldered on the lowerend of the feed casing l8".

In both of these modifications, the feed bars 26 26 can move freelythrough an annular path and can engage the lowest positioned leadcarrier by reason of the force of gravity.'

While I have shown and described what is now thought to be the preferredembodiments of my invention, the disclosure is to be regarded asillustrative only and not limitative except as hereinafter claimed.

' I claim:

1. A device of the class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriers mountedin one of said casings for independent sliding movement into and out ofan operative position, means for moving a selected lead carrier intoand. out of an operative position, said means being carried by saidother casing, said means comprising a feed bar freely mounted to permitat least the forward end thereof to move freely by gravity through anannular path, and means carried by said first casing and mounting saidcarriers in an annular ring adjacent the periphery of said first casing.I

A device of the class described, comprising .a pair of casingstelescopically connected 'toried by said first casing and mounting saidcarriers in an annular ring adjacent the periphery of said first casing,and the connection between said feed bar and said second casing being atthe end of said feed bar remote from said carriers.

3. A device of the class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriers mountedin one of said casings for independent sliding movement into and out ofan operative position, means for moving a selected lead carrier into andout of an operativeposition, said means being carried by said othercasing, said means comprising a feed bar freely mounted to permit atleast the forward end thereof to move freely by gravity through anannular path, means carried by said first casing and mounting saidcarriers in an an-'.

nular ring adjacent the periphery of said first casing, andsubstantially all of said feed bar being movable by gravity through anannular path.

4. A device of the class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriers mountedin one of said'casings for independent sliding movementinto and out ofan operative position, means for moving a selected lead carrier into andout of an operative position, said means being carried by said othercasing, said means comprising a feed bar freely mounted to permit atleast the forward end thereof to move freely by gravity through anannular path, means carried by said first casing and mounting saidcarriers in an annular ring adjacent the periphery of said first casing,the connection between said feed bar and said second casing being at therear end of said path.

5. A device of the 'class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriers mountedin one of said casings for independent sliding movement into and out ofan operative position, means for moving a selected lead carrier into andout of -an operative position, said means being carried by said othercasing, said means comprising a feed bar freely mounted to permit atleast the forward end thereof to move freely by gravity through anannular path, and means carried by said first casing and mounting saidcarriers in an annular ring adjacent the periphery 'of said firstcasing, said feed bar being'formed to provide a crank having one endthereof rotatably mounted in said second casing axially thereof.

6. A device of the class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriers mountedin one of said casings for independent sliding movement into and out ofan operative position, means .for moving a selected lead carrier intoand out of an operative position, said means being carried by said othercasing, said means comprising a feed bar freely mounted to permit atleast the forward end thereof to move freely by gravity through anannular path, means carried by said first casing and mounting saidcarriers in .an annular ring adjacent the periphery of said firstcasing, and an annular chamber formed in said second casing, the rearend of said feed bar being formed to provide an enlargement, saidenlargeried by said other casing, said means comprising forward endthereof to move freely by gravity through an annular path, means carriedby said first casing and mounting said carriers in an annular ringadjacent the periphery of said first casing, and a spring means normallypreventing the telescoping of said casings.

8. A device of the class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriersannularly carried by one of said casings for independent slidingmovement into and out of an operative position with respect thereto,means for moving a selected lead carrier into and out of an operativeposition, and means connecting said carrier moving means to the other ofsaid casings, said connecting means permitting free movement of saidcarrier moving means relative to said second casing, and said carriermoving means being movable by gravity to a carrier feeding positionrelative to that carrier nearest the lowermost side wall of said firstcasing when said pencil is held in any position other than substantiallyvertical.

9. A device of the class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriersannularly carried by'one of said casings for independent slidingmovement into and out of an operative position with respect thereto,means for moving a selected lead carrier into and out of an operativeposition, means connecting said carrier moving means to the other ofsaid casings, said connecting means permitting free movement of saidcarrier moving means relative to said second casing, and said carriermoving means being movable by gravity to a carrier feeding positionrelative to that carrier nearest the lowermost side wall of said firstcasing when said pencil is held in any position other than substantiallyvertical,'and said carrier moving means being operative upon rotation ofsaid device when so held to position itself automatically andsuccessively in positions to move all of said carriers.

10. A device of the class described, comprising a pair 'of casingstelescopically connected together, a plurality of lead carriersannularly carried by one of said casings for independent slidingmovement into and out of an operative position with respect thereto,means for moving a selected lead carrier into and out of an operativeposition, means connecting said carrier moving means to the other ofsaid casings, said connecting means permitting free movement of saidcarrier moving means relative to said second casing, and said carriermoving means being movable by gravity to a carrier feeding positionrelative to that carrier nearest the lowermost side wall of said firstcasing when said pencil is held in any position other than substantiallyvertical, said carrier moving means whereby rotation of said device whenso held automatically and successively positions said carrier movingmeans in positions tomove all of said carriers, and indicating means forenabling an operator to position said carrier moving means in a positionto move any selected carrier.

11. A device of the class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriers mountedin one of said casings for independent sliding movement into and out ofan operative position, means for moving a selected lead carrier into andout of an operative position, said means being carried by said othercasing, said means comprising a feed a feed bar freely mounted to permitat least the annular ring adjacent the periphery of said first casing,spring means normally preventing the telescoping of said casings,individual spring means normally maintaining each of said carriers in aninoperative position, and means carried by said first casing andengageable with a carrier when the same is moved to an operativeposition to maintain the same in such position against the action ofsaid spring.

12. A device of the class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriers mountedin one of said casings for independent sliding movement into and out ofan operative position, means for moving a selected lead carrier. intoand out of an operative position, said means being carried by said othercasing, said means comprising a feed bar freely mounted to permit atleast the forward end thereof to move freely by gravity through anannular path, means carried by said first casing and mounting saidcarriers in an annular ring adjacent the periphery of said first casing,spring means normally preventing the telescoping of said casings,individual spring means normally maintaining each of said carriers in aninoperative position, means carried by said first casing and engagcablewith a carrier when the same is moved to an operative positionto'maintain the same in such position against the action of said spring,and means automatically releasing said last named means to permit saidcarrier spring to retract said carrier when a second selected carrier ismoved towards an operative position.

13. A device of the class described, comprising a pair of casingstelescopically connected together, a member carried by one of saidcasings and dividing at least a portion of the same into a plurality oflongitudinally disposed and annularly arranged carrier receivingchambers, a lead carrier in each chamber, spring means in each of saidchambers and engageable with said carriers to maintain the same therein,means carried'by said other casing and engageable with a selectedcarrier for moving the same out of the chamber thereof into an operativeposition against the action of said spring, means for maintaining saidcarrier in an operative position, means for disengaging said carrierfrom said last named means to permit said spring to return said carrierto its chamber, and a portion of said chamber being formed to provideshock taking means to receive the recoil of said retracted carrier.

14. A device of the class described, comprising a pair of casingstelescopically connected together, a plurality of lead carriers mountedin one of said casings for independent sliding movement into and out ofan operative position, means for moving a selected lead carrier into andout of an operative position, said means being carried by said othercasing, said means comprising a feed bar freely mounted to permit atleast the forward end thereof to move freely by gravity through anannular path, meanscarried by said first casing and mounting saidcarriers in an annular ring adjacent the periphery of said first casing,alined slots through the overlapping portions of said casings, lugs onsaid carriers slidable in said slots, the slots of at least one casingbeing formed to provide offsets at one end thereof whereby rotation ofthe other casing when a carrier and lug have been slid to said endforces the lug of said carrier into said ofiset to lock said carrieragainst sliding movement and whereby rotation of said other casing inthe reverse direction re-positions said lug for sliding movement in saidslot.

15. A device of the character described comprising a casing, a pluralityof lead carriers annularly carried thereby for independent movement intoand out of an operative position at one end thereof, means for moving aselected lead carrier into and out of an operative position, meansmounting said carrier moving means, said mounting means permitting freemovement of said carrier moving means relative thereto, and said carriermoving means being movable by gravity to a carrier feeding positionrelative to that carrier nearest the lowermostside wall of said casingwhen said pencil is held in any position other than substantiallyvertical.

16. A device of the class described, comprising a casing, a plurality oflead carriers mounted in said casing for independent sliding movementinto and out of an operative position at one end of said casing, meansfor moving a selected lead carrier into and out of an operativeposition, said means comprising a feed bar freely mounted to permit atleast the forward end thereof to move freely by gravity through anannular path, and means carried by said casing and mounting saidcarriers in an annular ring adjacent the periphery of said casing.

1 KURT FEND.

Patented June 20, 1939 UNITED STATES PATENT OFFICE 77,453. In Great 8Claims.

In the manufacture of opaque glazes, enamels, engobe glass or the like,a known opacifier is zinc sulphide, preferably added to the batch or inthe operation of milling the frit or both to the batch and to the mill.

This invention is based on the observation that the effect of zincsulphide is improved, both in producing a whiter glaze or enamel and inrespect of the firing properties of the glaze, by the presence of zincoxide, and the invention consists in improving the production of opaqueglazes, enamels or the like by introducing zinc oxide into the glaze atsome stage of its manufacture or application.

The obvious method of introducing the zinc oxide into the glaze is bymixing the compound itself with the constituents of the batch, or,preferably, adding it to the mill during the grinding of the irit madefrom the batch. However, it is also possible to introduce into the batchor milled frit a product which will yield zinc oxide during the smeltingof the bath or the firing of the glaze, for instance zinc carbonate orzinc acetate; of course, in this case care must be taken that thedecomposition or reaction which produces .the zinc oxide in the glazehas no deleterious efiect on the glaze.

The proportion of zinc oxide to zinc sulphide which gives the bestresult must be ascertained by trial, since it varies with the type ofglaze that is to be produced and with the type of clay used EfQI'floating the glaze. The main result to ;be sought is maximum whitenessof the finished glaze, but in some cases this is only attainable withloss of capacity, so that the proportion of zinc oxide may be betterselected slightly below that which produces maximum whiteness. Otheropacifiers, including the so-called gas opacifiers may be simultaneouslyused with advantage to produce maximum opacity and whiteness.

The following is an example of the production of a white opaque enamelon metal hollow-ware, in accordance with the invention:

A batch consisting, in parts by weight of:

Borax 360 Felspar 448 Quartz 280 Soda ash 112 50 Sodium silicofiuoride112 Fluorspar 60 is mixed with parts of zince oxide and the mixture issmelted until the smelt is quiet; the mass is then quenched with water.The frit thus produced is dried and milled with, per 100 parts,

Britain May 1, 1935 10 parts of White clay, 6 parts of zinc sulphide, 7parts of zinc oxide and 45-50 parts of water, and further milled to asuitable grade of fineness. Other additions, for example sodium nitriteamounting to 1 per cent. of the weight of the frit, may be made toimprove further the whiteness or setting properties, or both, of theenamel. The enamel is applied and fired in the usual manner.

An alternative procedure is to add part or all of the zinc sulphide tothe batch before smelting and to add the desired quantities of zincoxide as described above. The zinc sulphide may be formed by using analkali sulphide and a suitable zinc compound as constituents of thebatch or as additions to the mill.

It is not at present known Whether the zinc oxide added to or producedin the glaze remains as such in the finished glaze.

The term zinc sulphide as employed in the specification and appendedclaims is understood to apply to ordinary zinc sulphide and does notembrace the so called luminescent sulphides of zinc which have undergonea special treatment and contain excitants which render the substanceself-luminous.

Having thus fully described the nature of my said invention and the bestmeans I know of carrying the same into practical effect, I declare thatwhat I claim is:

1. The improvement in the production of glazes, enamels or the likewhich contain ordinary zinc sulphide as an opacifier, which consists inintroducing zinc oxide into the glaze at some stage of its manufactureor application.

2. A manufacture of an opaque glaze or enamel for application to ceramicWare or metal-ware, wherein zinc oxide is used to improve the whitenessof the opacity in the finished glaze due to ordinary zinc sulphide.

3. A batch which is to be used for producing a glaze that has opacitydue to ordinary zinc sulphide, characterised by containing zinc oxide ora product which will yield zinc oxide during the smelting of the batchor the firing of the glaze.

4. A frit for producing on ceramic ware or metal ware a glaze which hasopacity due to ordinary zinc sulphide, characterised by containing zincoxide or a product which will yield zinc oxide during the firing of theglaze.

5. Articles glazed with a glaze made from the batch defined in claim 3,

6. Articles glazed with a glaze made from the frit defined in claim 4.

